// v1.14.x-html-artifact-panes: extracted from MessageBubble.tsx so both the
// in-chat bubble renderer and the MarkdownArtifactPane share the same Shiki +
// remark-gfm + path-linkifier pipeline. Behavior preserved byte-for-byte from
// the original MessageBubble.MarkdownBody helper (and its linkify helpers).
import { Children, cloneElement, isValidElement } from 'react';
import type { ReactElement, ReactNode } from 'react';
import Markdown from 'react-markdown';
import remarkGfm from 'remark-gfm';
import { CodeBlock } from './CodeBlock';
import { sessionEvents } from '@/hooks/sessionEvents';

// Match path-shaped substrings ending in `.ext`. Additionally require a `/`
// in the match to reduce false positives in prose (e.g. plain `foo.ts` won't
// match, but `src/foo.ts` will). False positives at the edges are accepted
// per Sam's design decision (2026-05-14).
const PATH_REGEX = /([a-zA-Z0-9._/-]+\.[a-zA-Z0-9]+)/g;

function isPathLike(s: string): boolean {
  return s.includes('/');
}

function emitOpenFile(path: string): void {
  sessionEvents.emit({ type: 'open_file_in_browser', path });
}

function linkifyPaths(text: string, keyPrefix: string): ReactNode {
  const out: ReactNode[] = [];
  let lastIdx = 0;
  let idx = 0;
  for (const match of text.matchAll(PATH_REGEX)) {
    const matchedText = match[0];
    const start = match.index ?? 0;
    if (!isPathLike(matchedText)) continue;
    if (start > lastIdx) out.push(text.slice(lastIdx, start));
    out.push(
      <button
        key={`${keyPrefix}-${idx}`}
        type="button"
        onClick={() => emitOpenFile(matchedText)}
        className="text-primary underline cursor-pointer hover:text-primary/80"
      >
        {matchedText}
      </button>
    );
    lastIdx = start + matchedText.length;
    idx += 1;
  }
  if (out.length === 0) return text;
  if (lastIdx < text.length) out.push(text.slice(lastIdx));
  return out;
}

function linkifyChildren(children: ReactNode, keyPrefix = 'l'): ReactNode {
  const arr = Children.toArray(children);
  return arr.map((child, i) => {
    if (typeof child === 'string') {
      return (
        <span key={`${keyPrefix}-${i}`}>
          {linkifyPaths(child, `${keyPrefix}-${i}`)}
        </span>
      );
    }
    if (isValidElement(child)) {
      const el = child as ReactElement<{ children?: ReactNode }>;
      if (el.type === 'code' || el.type === CodeBlock) return child;
      const grandchildren = el.props.children;
      if (grandchildren === undefined) return child;
      return cloneElement(el, {
        key: el.key ?? `linkified-${i}`,
        children: linkifyChildren(grandchildren, `${keyPrefix}-${i}`),
      });
    }
    return child;
  });
}

const codeRenderer = (props: { children?: unknown; className?: string }) => {
  const { children, className, ...rest } = props;
  const text = String(children ?? '').replace(/\n$/, '');
  const langMatch = /language-([\w-]+)/.exec(className ?? '');
  const isBlock = !!langMatch || text.includes('\n');
  if (isBlock) {
    return <CodeBlock code={text} lang={langMatch?.[1]} />;
  }
  return (
    <code
      {...rest}
      className="rounded bg-muted px-1 py-0.5 font-mono text-[0.85em]"
    >
      {children as React.ReactNode}
    </code>
  );
};

export function MarkdownRenderer({ content }: { content: string }) {
  return (
    <Markdown
      remarkPlugins={[remarkGfm]}
      components={{
        pre: ({ children }) => <>{children}</>,
        code: codeRenderer,
        a: ({ children, href }) => (
          <a
            href={href}
            target="_blank"
            rel="noreferrer"
            className="underline decoration-muted-foreground/40 underline-offset-2 hover:decoration-foreground"
          >
            {children}
          </a>
        ),
        ul: ({ children }) => (
          <ul className="list-disc pl-5 space-y-1">{children}</ul>
        ),
        ol: ({ children }) => (
          <ol className="list-decimal pl-5 space-y-1">{children}</ol>
        ),
        li: ({ children }) => <li>{linkifyChildren(children)}</li>,
        p: ({ children }) => (
          <p className="leading-relaxed">{linkifyChildren(children)}</p>
        ),
        h1: ({ children }) => <h1 className="text-base font-semibold mt-2">{children}</h1>,
        h2: ({ children }) => <h2 className="text-sm font-semibold mt-2">{children}</h2>,
        h3: ({ children }) => <h3 className="text-sm font-semibold mt-1">{children}</h3>,
        blockquote: ({ children }) => (
          <blockquote className="border-l-2 border-border pl-3 text-muted-foreground">
            {children}
          </blockquote>
        ),
        table: ({ children }) => (
          <div className="overflow-x-auto">
            <table className="border-collapse text-xs">{children}</table>
          </div>
        ),
        th: ({ children }) => (
          <th className="border border-border px-2 py-1 text-left font-medium">{children}</th>
        ),
        td: ({ children }) => (
          <td className="border border-border px-2 py-1">
            {linkifyChildren(children)}
          </td>
        ),
      }}
    >
      {content}
    </Markdown>
  );
}